Phytochemistry Reviews (v.17, #5)

Trends in natural product research: PSE young scientists’ meeting Lille 2017 by Céline Rivière; Jean-Louis Hilbert (947-949).

The interest in using the ‘-omics’ approach for nutrition, agriculture, food science and human health have seen an explosive growth in the last years. Particularly, metabolomics analysis is becoming an integral part of a system biological approach for investigating organisms. In this review, the limitations and advantages of NMR spectroscopy and mass spectrometry were discussed in details using the study reported in the literature on different Salvia species (S. hispanica, S. miltiorrhiza, S. officinalis, S. runcinata and S. stenophylla). Both approaches identify and quantify several classes of compounds but not the complete metabolite profile of the plant. A combined approach of these two powerful techniques provides better results allowing to determine both primary and secondary metabolites.
Keywords: Metabolomics; Salvia ; Sage; NMR; MS; Multivariate data analyses

Recent advances in chemistry, therapeutic properties and sources of polydatin by Didem Şöhretoğlu; Merve Yüzbaşıoğlu Baran; Randolph Arroo; Ayşe Kuruüzüm-Uz (973-1005).
Polydatin (PLD), the 3-O-β-glucopyranoside of the well-known stilbenoid compound resveratrol, is a major compound of Fallopia japonica (Houtt.) R. Decr. (Japanese knotweed), which is widely used in traditional Chinese medicine to treat infection, inflammatory diseases and circulatory problems. It has shown a wide range of biological activities including anti-inflammatory, anti-oxidant, anti-cancer, neuroprotective, hepatoprotective, nephroprotective and immunostimulatory effects. Although resveratrol has similar beneficial effects, its low bioavailability has remained a problem. Glycosylation increases solubility of resveratrol in an aqueous environment, thus improving its bioavailability. This has led to a growing interest in PLD. Promising results obtained from bioactivity studies have boosted an intense research on this compound. The aim of this review is to give a comprehensive overview of the botanical sources, pharmacology, biosynthesis, biotechnological production, and bioactivities of PLD, and to discuss clinical studies on this compound.
Keywords: Polydatin; Piceid; Stilbene; Trans-resveratrol 3-O-glucoside

A review of dietary stilbenes: sources and bioavailability by Toni El Khawand; Arnaud Courtois; Josep Valls; Tristan Richard; Stéphanie Krisa (1007-1029).
Stilbenes are a class of phenolic metabolites found in various edible plants, such as grapevine, berries and peanuts. Their bioactivitiy and their potential benefits for human health have been the subject of several studies. Among all identified stilbenes, resveratrol has been particularly studied and results from literature showed that it presents several biological activities, including antioxidant, anti-inflammatory and antiproliferative effects. Likewise, some researches focused on other stilbenes and highlighted similar biological activity for those compounds. However, stilbenes present a high diversity in their phenolic structures (various chemical substituents and polymerization) which is a determining factor of their absorption and metabolism rates. Consequently, this could affect the effectiveness of stilbenes in vivo. In this context, an evaluation of the bioavailability and metabolism of stilbenes is necessary to move forward with pharmacological and clinical studies. Hence, this review aims to present recently obtained data and results concerning stilbenes sources and bioavailability, as a contribution to the valorization of the role of dietary stilbenes in the human diet.
Keywords: Bioavailability; Metabolism; Pharmacokinetics; Stilbenes

Phenolic antioxidants of Morus nigra roots, and antitumor potential of morusin by Zoofishan Zoofishan; Judit Hohmann; Attila Hunyadi (1031-1045).
Phenolic compounds are of considerable biomedical interest due to their antioxidant properties and potential in the prevention and possibly treatment of many chronic diseases. The fruits, leaves and root bark of Morus nigra (Moraceae), the black mulberry tree, have a long history of use for various therapeutic purposes in traditional medicine worldwide. The roots of the plant are known to be a rich source of phenolic compounds with a particularly high chemical diversity. This mini-review compiles the currently available knowledge on phenolic compounds reported from Morus nigra roots, and provides a brief overview on the antioxidant activity with a focus on the available in vivo evidence. Morusin, a major phenolic antioxidant of the root bark, has attracted a rapidly increasing scientific interest for its versatile and potent antitumor properties; recent developments in this regard, including morusin’s promising activity against cancer stem cells, are also discussed in the paper.
Keywords: Anticancer activity of prenylflavone; Black mulberry root bark; Cancer stem cell; Ethnopharmacology; In vivo antioxidant activity

Humulus lupulus L. (Cannabaceae), commonly named hop, is widely grown around the world for its use in the brewing industry. Its female inflorescences (hops) are particularly prized by brewers because they produce some secondary metabolites that confer bitterness, aromas and antiseptic properties to the beer. These sought-after metabolites include terpenes and sesquiterpenes, found in essential oil, but also prenylated phenolic compounds, mainly acylphloroglucinols (bitter acids) from the series of α-acids (humulone derivatives). These metabolites have shown numerous biological activities, including among others, antimicrobial, sedative and estrogenic properties. This review provides an inventory of hop’s chemistry, with an emphasis on the secondary metabolites and their biological activities. These compounds of biological interest are essentially produced in female inflorescences, while other parts of the plant only synthetize low quantities of them. Lastly, our article provides an overview of the research in plant biotechnology that could bring alternatives for hops metabolites production.
Keywords: Hop; Humulus lupulus L.; Phytochemistry; Biological activities; Plant biotechnology

Chemical composition and nutritional function of olive (Olea europaea L.): a review by Zebin Guo; Xiangze Jia; Zhichang Zheng; Xu Lu; Yafeng Zheng; Baodong Zheng; Jianbo Xiao (1091-1110).
The olive (Olea europaea L.) is a widely-distributed plant that originated in the Mediterranean region. Its fruit is commonly used to produce olive oil, table olives, and other by-products. The main nutrient of the olive fruit is fat, predominantly monounsaturated fatty acids (MUFA). Olives are also rich in carbohydrates, vitamins, and minerals. Increasing numbers of investigations show that the health benefits of the ‘Mediterranean diet’ are associated with lower incidences of chronic degenerative diseases and higher life expectancy. These benefits have been attributed to the dietary consumption of olive oil. Furthermore, epidemiological data suggest that phenolic components and other antioxidants in olive oil are responsible for some of these benefits. Remarkably, these minor components play significant roles in reducing the incidences of atherosclerosis, cardiovascular disease, neurodegenerative diseases, and certain types of cancer. We reviewed the main olive products and the nutritional composition of olive oil focusing on fatty acids, phenolic compounds, and other antioxidants. We also discuss the chief chemical constituents relevant to the biological activity of olive oil, the metabolism and bioavailability of olive oil phenolic compounds, and the antioxidant activity of metabolites. Finally, we outline recent advances, potential applications, and limitations of developments in the olive oil industry, aiming to provide a theoretical basis for further research and to broaden the prospect of its application to healthy diets.
Keywords: Nutrition; Chemical composition; Olive products; Function; Bioactivity

There is a global increase in the incidence of diabetes mellitus (DM). Hyperglycemia is one of the prevailing conditions which gives rise to various diabetic complications. The major complications include diabetic nephropathy, retinopathy, neuropathy, delayed wound healing, heart attack, peripheral vascular disturbances and diabetic ketoacidosis. Treatment of complications due to DM always poses a challenge to the attending clinician. Alongsideallopathic medicines, DM and its complications were reported to be effectively treated with various natural products. In the present review, we discuss the role of different phytochemicals which were reported to be beneficial in the treatment of hyperglycemic conditions in DM. Most medicinal plants contain micronutrients, amino acids and proteins, mucilages, essential oils, sterols and triterpenoids, saponins, carotenoids, alkaloids, flavonoids, phenolic acids, tannins, bitter principles and coumarins. We discuss the effective role of these phytochemicals with an emphasis on secondary metabolites which mimic the action of insulin, and highlight their importance as future antidiabetic agents.
Keywords: Diabetes mellitus; Hyperglycemia; Complications; Treatment; Phytochemicals

Staphylococcus aureus infections are considered as seriously problematic for human health and necessitate the development of new medicines and innovative antimicrobial strategies. Plant secondary metabolites have already demonstrated their potential as antibacterials when used alone but also in combination with other antimicrobial agents to potentiate their activity. Triterpenoids are widely distributed in the plant kingdom and known to have many beneficial effects, including anti-inflammatory, immunomodulatory, anti-proliferative, antimycotic, or antimicrobial activity. The aim of this paper is to review the activity of pentacyclic triterpenoids belonging to the ursane, oleanane, or lupane groups against Staphylococcus aureus. We summarize their activity as anti-staphylococcal compounds but also as resistance modifying agents when combined with common antibiotics.
Keywords: Ursane; Oleanane; Lupane; MIC; FICI; Staphylococcus aureus

Phytochemical review of the lichen genus Stereocaulon (Fam. Stereocaulaceae) and related pharmacological activities highlighted by a focus on nine species by Friardi Ismed; Françoise Lohézic-Le Dévéhat; Annie Guiller; Nina Corlay; Amri Bakhtiar; Joel Boustie (1165-1178).
The Stereocaulon genus is one of the fruticose lichen groups distributed worldwide from tropical zones to polar zones. However, the scientific study of this tricky genus is still limited, making it a challenge to study the group further. Detailed morphological studies are essential to discriminate closely shaped species which is illustrated through personal data focused on phyllocladia, apothecia and spores of nine species. Secondary metabolites isolated from Stereocaulon species are mostly some depsides, depsidones, diphenylethers and dibenzofurans which can have a taxonomic value. The use of Stereocaulon lichens as a traditional medicine in several regions of the world and pharmacological studies of extracts and isolated compounds have been compiled. Biological activities as cytotoxic, anti-inflammatory, antibacterial, antifungal or antioxidant are reported.
Keywords: Biogenetic; Bioactivities; Folk medicines; Lichens; Secondary metabolites; Stereocaulon

Polar lipids in cosmetics: recent trends in extraction, separation, analysis and main applications by Mégane Traversier; Thomas Gaslondes; Sandrine Milesi; Sylvie Michel; Eldra Delannay (1179-1210).
Demand for active, natural, safe and biomimetic (similar to human molecules) plantderived cosmetic ingredients is always greater because consumers are increasingly suspicious of the potential toxicity of current ingredients. In this context, interest has increased for polar lipids like ceramides, sphingolipids or glycolipids that share structural properties with the skin lipids. In the same manner, processes to obtain such lipids should be driven by the principles of green chemistry and sustainable development. The identified needs are biodegradability, biocompatibility, efficiency, quality and profitability. In this research for new and novel natural or ‘green’ compounds, the development of bioactive lipids thanks to ecofriendly processes has obviously intensified, especially for cosmetic and agro-food industries. This paper reviews extraction methods for polar lipids (glycolipids and phospholipids), especially ecoprocesses (supercritical fluid extraction, microwaves, sonication, enzyme extraction…), and promising chromatographic methods like countercurrent chromatography, supercritical fluid chromatography or high performance chromatography coupled to mass spectrometry Interests of polar lipids for cosmetic industries are exemplified to show their broad applications mostly relying on their amphiphilic properties allowing them to play functional roles (liposome or micelle structures for example) or physiological roles (skin barrier function or anti-ageing effect).
Keywords: Phospholipids; Glycolipids; Ecoprocess extractions; Biosurfactant; Skin-care

In Rio de Janeiro, in order to preserve biodiversity a virtuous circle was set up in 1992: The sustainable use of biodiversity (genetic resources) will generate benefits which will then be used to preserve biodiversity. The Nagoya Protocol elaborated in 2010 was designed to bring clarification and allow the practical implementation of this virtuous circle of access and benefit sharing. The scope was clarified: research on genetic and biochemical content of plants, animals, fungi and microorganisms. Since many countries have now implemented access rules, it is important for academic and industrial users of biological resources to be fully aware of the regulations and to respect them.
Keywords: Access to biodiversity; Convention on Biodiversity; Nagoya Protocol; Traditional knowledge